<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"

>
<head>
    <meta charset="UTF-8">
    <title>Hello World!</title>
</head>
<body>
<div>
    <textarea id="text"  style="height: 300px;width:300px;background-color: cyan">
    </textarea>
</div>
<div>
    <textarea id="message" style="height: 300px;width:300px">

    </textarea>
</div>
<button onclick="send()">发送</button>
<button onclick="closeWebSocket()">关闭</button>
</body>
<script>
    var websocket = null;
    //判断当前浏览器是否支持WebSocket
    if ('WebSocket' in window) {
        websocket = new WebSocket("ws://127.0.0.1:8907/websocket");
        alert("连接成功");
    }
    else {
        alert('Dont support websocket')
    }

    //连接发生错误的回调方法
    websocket.onerror = function () {
        setMessageInnerHTML("error");
    };

    //连接成功建立的回调方法
    websocket.onopen = function (event) {
        setMessageInnerHTML("open");
    }

    //接收到消息的回调方法
    websocket.onmessage = function (event) {
        console.log(event.data);
        setMessageInnerHTML(event.data);
    }

    //连接关闭的回调方法
    websocket.onclose = function () {
        setMessageInnerHTML("close");
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function () {
        websocket.close();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

    //关闭连接
    function closeWebSocket() {
        websocket.close();
    }

    //发送消息
    function send() {
        var message = document.getElementById('text').value;
        websocket.send(message);
        setMessageInnerHTML(message);
    }
</script>
</html>